Laser Light Induced Transformation of Molybdenum Disulphide-Based Nanoplatelet Arrays.

One-pot hydrothermal synthesis of MoS nanoplatelet arrays on various substrates is perhaps the most promising approach to fabricate efficient electrocatalysts for hydrogen evolution reaction. However, the main challenges in this synthesis remain the purity and crystallinity of MoS. In this study, we show for the first time that irradiation of amorphous, defect-rich MoS nanoplatelets with a green nanosecond laser at a proper irradiation dose, ca ≤0.35 J cm, can significantly improve the crystallinity and purity of MoS nanoplatelets. The effect was confirmed by Raman spectroscopy investigations demonstrating a surprising intensity increase of the A and modes after the laser irradiation. Further increase of irradiation energy, however, resulted in the photocorrosion and destruction of MoS nanoplatelets. The variation of A and Raman mode intensities ratio depending on the green light irradiation dose was also presented and is discussed below.